Viral release and membrane acquisition by budding through the nuclear envelope of hemocytes of the gypsy moth, Porthetria dispar

Viral particles of the nuclear polyhedrosis virus (Baculovirus) of the gypsy moth, Porthetria dispar, appear to be released from hemocyte nuclei by budding through both inner and outer lamellae of the nuclear envelope. As a result of budding, the virus particle acquires its envelope from the inner lamella of the nuclear envelope. The outer lamella, which forms a membrane-limited vesicle around the enveloped particles, may fuse with the plasma membrane during viral release from host cells by exocytosis. These observations differ from two other reported cases of nuclear budding in NPV-infected cells in that the process occurred in the absence of nuclear inclusion bodies.